While the A/C is on, The Jeep randomly blows HOT air from the floor vents for 3-5 mins then stops

drfeli

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Mine started the first week and now has 4K miles. Does it several times and hour on a long road trip. Appears to be some type of flap opening behind the dashboard. When glove box is open you can feel the air coming from there too. Dash vents never stop blowing cold. I sent vin and miles to jeep cares. Unfortunately I don’t have time to drop it off for several days for the dealer to tell me they xmcant duplicate the problem. Maybe in a couple of weeks Only way to duplicate is to drive it until it happens. Maybe an hour maybe less.





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JeepCares

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Have a brand new JLUR. Doing the same thing. Randomly blowing warm/humid at the feet on passenger side. A/C is set to dash vents only. Recirculation is OFF. Warm air only lasts a couple of minutes. Dash vents keep blowing cool air.
Took it to the Dealer yesterday. Dealer turned it into Jeep and received this response: "You can perform a system calibration of the HVAC door actuators if you like but no DTCs correct? Normally with the recirculation door on too long the vehicle calls for fresh air to be brought in for a short amount of time and during that event a Ram Air effect will allow the passenger side to only feel that event." Ok, but I told the dealer we experience the event when the recirculation is off. The system is already bringing in outside air.
Hi Tototrvlr,

We want to make sure that we have this documented. Can you please send us your VIN and mileage through a PM?

Darlene
Jeep Social Care Specialist
 

WranglerMan

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I don’t use ESS and have recirc on all the time and temps are synced all the time as it’s just to dam hot here in Houston, I honestly don’t think we need fresh hot air brought in from the outside as the Jeep in itself is not airtight so IMHO this design needs to be addressed and possibly removed thru a software update.
 

cobra

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Has anyone determined if the hot air is flowing past the heater core or does it seem to be air from outside at ambient temperature?

What a strange phenomenon. Why couldn’t Jeep just design the system to open the recirculation gate periodically if they were worried about O2 rather than pump uncooled air to the heater vents?

If what FCA claims is true, then wouldn’t the same thing happen in the winter? You would get a blast of cold air unless it is flowing past the heater core first.
I got my jeep in feb and i remember my wife saying all of a sudden cold air is coming in on the pass side periodically. Didn't do anything about it but i was riding in the pass side the other day and it would at times blow hot air in so i'm on the list too.
 

Jeepsterfreak

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I got my jeep in feb and i remember my wife saying all of a sudden cold air is coming in on the pass side periodically. Didn't do anything about it but i was riding in the pass side the other day and it would at times blow hot air in so i'm on the list too.
Interesting. So maybe there is a separate air inlet when opened allows outside air to enter the passenger side vent but bypasses the heater core and evaporator.

Someone will have to go searching for it. Maybe it can be disabled.
 

NavyVet1959

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Interesting. So maybe there is a separate air inlet when opened allows outside air to enter the passenger side vent but bypasses the heater core and evaporator.

Someone will have to go searching for it. Maybe it can be disabled.
But the question would then be whether disabling it causes more problems than it solves?
 

cobra

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My dealer is going to do a software update next week, we'll see if it helps.
 

Jeepsterfreak

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But the question would then be whether disabling it causes more problems than it solves?
True. I have no idea if there is a separate air inlet or not, but from the description by members it sure seems like it. It sounds like this outside air is not flowing past the evaporator or heater core and is being diverted directly to the passenger footwell vent? Have to wonder if this outside air flows through the air inlet filter or if completely separate inlet.

Just seems odd to design a system this way rather than just having the software turn off the recirc momentarily.

Maybe the auto industry is worried about carbon dioxide poisoning. Is this a European thing?
 

Jlo_1212

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We just took my JLU sport to Indiana for my brothers wedding and definitely noticed this happening. The weird thing is we were on the highway and the air was on (no auto). It was set to low and fan was at 4.
YepThis exactly. Driving across alligator alley, temp set at 68 (not auto) and periodically the a/c would kick out and start blowing hot for like 20 sec or so.
 

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I've noticed a lot of heat on the drivers side on long highway trips, I thought it was heat coming through the floorboards. I'm going to have to pay closer attention to see if it's air vs. conductive.
 

Jeepsterfreak

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I've noticed a lot of heat on the drivers side on long highway trips, I thought it was heat coming through the floorboards. I'm going to have to pay closer attention to see if it's air vs. conductive.
Keep your A/C blowing on the dash vents then see if your feet get hit with warm air from the footwell vents while cold air is still blowing from the dash. That seems to describe most of the complaints.
 

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Here is my experience at the dealer and some info straight from FCA via the dealer.

I have the problem you are all describing. It will be blowing nice cold air and then POOF a blast of hot humid air will blow in on the floor for a very brief moment. While at dealer I mentioned it and they said there is an A/C software update but they don't know what the update exactly does, they just know there is an update. So they do the update and within the hour FCA is on the phone with the servivce manager because he saw my complaint and software update hit their system. He asked him what am I experiencing so the service manager told him and the FCA rep said the following...
"Owners are experiencing lack of cooling or bursts of hot humid air. Check the lower left corner of the condenser for leaks if A/C is not blowing cold enough (they have some leaking units). For the bursts of hot air explain to the customer that if you are driving for long periods of time with the recirc button on the computer will open the damper and allow a burst of outside fresh air in so that oxygen levels will not get low" NO I'm not making this up!
He also said that this occurs while it is on MAX A/C only but I told that service manager that's not true.

The service manager was kind of chuckling and says that this falls under "normal" because the Jeep was designed that way. I told him I have tried to replicate it by opening the recirc damper and can't get the same effect which leads me to believe there may be another port which allows this air in. When I simply hit the recirc button to go to fresh air the A/C easily handles the humid air from outside and chills it. If there is some other damper we don't know about that allows straight up hot air in directly from the outside that would explain it.
So... it is normal BUT maybe this software will do something. The longer you drive the more likely it will happen because the computer reads the recirc closed longer. I'll see if it resolves the issue and post back.

My wife said the same guy who designed the A/C to work like this was probably the one to have auto stop/start set to on :mad:

@ JeepCares you are correct that people need to report this. This is on FCA's radar and they are aware of the issue. The more reports the more likely to keep progress on it.

https://www.jlwranglerforums.com/forum/members/13530/
Thanks for posting this follow up. I experienced this problem ~2 weeks ago on a road trip to FL. Was cool to find this thread via search and sharing info, so I'll try to do the same :)

On our recent return trip from FL I was really bored and was able to do some testing /shrug

I could see how auto or recirc could have some sort of air exchange to maintain temperature. So i went with various combinations of fan speed, recirc, face/foot, sync / nonsync, defrostoer -all on manual mode.

Sadly it still did it. It appeared worse hotter more humid southeast (FL/GA/SC/NC) and is about that bad in a heat-weave we're having now.

Jeep Cares on this forum did reach out to me and also followed up when i didn't respond in a few days or so. I just followed up today. Hope to get it in for service when i can.

I'll mark the post and hope i can follow up soon.

Thanks!
 

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Keep your A/C blowing on the dash vents then see if your feet get hit with warm air from the footwell vents while cold air is still blowing from the dash. That seems to describe most of the complaints.
+1 .Air is still cold from the dash but feels slightly less intense. I could feel with my hands where the warm humid air was coming from (in the foot well area), but did't feel air was blowing hard. Is just was warm and humid. I was bored on a road trip.
 

Sucram

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Keep your A/C blowing on the dash vents then see if your feet get hit with warm air from the footwell vents while cold air is still blowing from the dash. That seems to describe most of the complaints.
+1 .Air is still cold from the dash but feels slightly less in intense. I could tried to feel with my hands where the warm humid air was coming from in the foot well area but it did't feel air was blowing hard but is was warm and humid.

PS.
 

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Mines blowing cold air out the glovebox. Wtf
 

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